add sorbet installer

installer/install-sorbet.cmd

@@ -0,0 +1,18 @@
+@echo off
+
+echo @echo off ^
+
+setlocal ^
+
+set TARGET_DIR=%%1 ^
+
+shift ^
+
+cd %%TARGET_DIR%% ^
+
+bundle exec srb typecheck %%* ^
+
+> sorbet.cmd
+
+echo Install Done.
+echo **You need add sorbet dependencies in Gemfile.**

installer/install-sorbet.sh

@@ -0,0 +1,17 @@
+#!/bin/sh
+
+set -e
+
+cat <<EOF >sorbet
+#!/bin/sh
+
+TARGET_DIR=\$1
+shift
+cd \${TARGET_DIR}
+bundle exec srb typecheck \$*
+EOF
+
+chmod +x sorbet
+
+echo 'Install Done.'
+echo '**You need add sorbet dependencies in Gemfile.**'